Here's the fast lane of airport screening

More than 25 million people have left their coats and shoes on their bodies, their laptops and 3-ounce liquids packed away and walked through a metal detector rather than a body scanner since the 2011 launch of the Transportation Security Administration's PreCheck program.

But being picked for expedited airport security has been something of a tough get: Passengers have been eligible only by invitation from an airline or through membership in existing programs such as Global Entry.

Around Thanksgiving, the TSA also began extending PreCheck to random travelers deemed safe by the agency.

The program, however, is about to become a full-on part of the travel landscape.

This month the TSA began offering travelers the opportunity to apply for PreCheck status, which requires a background check, a visit to an airport application site and $85 for a five-year membership. The TSA plans to open more than 300 application centers across the nation, which effectively will democratize the opportunity to apply for PreCheck membership.

PreCheck's growth is part of what TSA spokeswoman Ann Davis called the agency's commitment to moving away from a "one-size-fits-all approach to screening, based on the knowledge that most passengers are low risk."

"We're breaking the travel population into subgroups and deciding, based on risk, whether we can offer them an expedited screening experience," she said.

Such philosophy has dictated that travelers 12 and younger and 75 and older generally get modified screenings.

"Intelligence tells you children 12 and under and people older than 75 are generally a low risk," Davis said.

It's important to note that those in PreCheck won't get expedited screening every time they travel. "We infuse some element of unpredictably for security purposes," Davis said.

Such organizations as the Global Business Travel Association and conservative think tank Heritage Foundation have applauded the expansion of PreCheck.

But Jay Stanley, a senior policy analyst with the American Civil Liberties Union, sounded caution, saying that PreCheck's information-gathering techniques are murky and that the program creates "a flying underclass."

"This is what we warned about since the beginning (of PreCheck in 2011): a de facto standard where everyone has to go through a background check to have a normal flying experience," Stanley said.

"Never before has the government rated its own citizen according to how dangerous they supposedly are. We live in a democracy where all people are supposed to be treated equal."

He also cautioned against its effectiveness: "A decorated military veteran like Timothy McVeigh probably wouldn't have had a hard time getting into this program."

George Hobica, founder of AirfareWatchdog website, said he supports the expansion because "it will make it less exclusive, which is good because the lines are faster. You really breeze through."

He agreed that PreCheck essentially amounts to profiling by the government, but he added that he has no objection.

"Is profiling a good thing?" he asked rhetorically. "The Israelis have done it for decades, and look at their record of air safety."